Radio telegraph system with direction control



Mayzs, 1951 L. M. Pons 1 2,554,793

RADIO TELEGRAPH SYSTEM WITH DIRECTION CONTROL MARTHA W. C. POTTS, EXECUTRIX Bvwm ATTORNEY L. M. POTTS RADIO TELEGRAPH SYSTEM WITH DIRECTION CONTROL May 29, 1951 7 Sheets-Sheet 2 Filed Jun-a 11. 1947 7 MTM- WEST INVENTOR LOUIS M. POTTS, DECEASED MARTHA W. C. POTTS, EXECUTRIX BY ZZ Z ATTORNEY May 29, 1951 I M. PoTTs 2,554,793

RADIO TELEGRAPH SYSTEM WITH DIRECTION CONTROL :E I :M E I ues-E F|G 3 |oe-E i L mi I m EAST L. l

lNvaNToR ATTORNEY May 29, 1951 M. PoTTs 2,554,793

RADIO TELEORAPH SISTEM WITH DIRECTION CONTROL Filed June 11, 1947 7 sheets-sheet 4 LOUIS M. PLOTTS, DECEASED MRTH W. C. POTTS, EXECUTRIX BOY ATTORNEY May 29, 1951 L. M. PoTTs 2,554,793

l RADIO TELEGRAPH SYSTEM WITH DERECTION CONTROL TSheets-Sheet 5 Filed June 11, 1947` lNvENToR LOUIS M. POTTS, DECEASED MARTHA W. C. POTTS, EXECUTRIX wf BY MM WATTORNEY l 246i 2g/244m May 29, 1951 M: Po'rTs RADIO TELL-:GRAPH SYSTEM WITH DIRECTION CONTROL '7 Sheets-Sheet 6 Filed June 11, 1947 JIT-E 9 E 3 n E L. Q W 3 4 .=...E 44. wm. n (ub 3 .d c... m. I L E 4. 152i.; H 64T 3 2 S m A Je F E m. 2

VIA wm. SU AC EE CX EE D Y mw S E TST N NTT WOP n IPC. Mw. mf MJ/U WT R l May 29, 1951 M. PoTTs 2,554,793

RADIO TELEGRAPH SYSTEM WITH DIRECTION CONTROL Filed June 11, 1947 -7 sheets-sheet 7 FlG. 7

EAST

gM/ENToR LOUIS M. POTTS, naci-:Assn MARTHA w. c, POTTS, ExEcuTRlx ATTORNEY Patented May 29, 1951 RADIO TELEGRAPH SYSTEM WITH DIRECTION CONTROL Louis M. Potts, deceased, late of Evanston, Ill., by Martha W. C.. Potts, executrix, Evanston, Ill., assignor to Teletype Corporation, Chicago, Ill., a corporation of Delaware Application June 11, 1947, serin1N0.754,o31

(C1. 25o-s) 6 Claims. l A

This invention relates to telegraph systems and particularly to a system having means for automatically controlling the direction of transmission.

An object of the present invention is to provide in a telegraph system, means for automatically changing the direction of transmission.

A further object of the invention is to provide in a telegraph system having individual stations each equipped with a transmitter, a home record printer and a receiving only printer, direction control means which automatically changes the direction of transmission, disables the transmitter and home record printer of the station about to receive and conditions its receiving only printer for operation and at the same time disables the receiving only printer of the station about to transmit and conditions its transmitter and home record printer for operation.

An additional object of the invention is to provide a telegraph system in which the direction of transmission is automatically reversed after a message has been transmitted.

Other objects and advantages of the invention will appear as the invention is described in detail and restrictions of the scope of the invention should not be implied from the specific recital of the above appearing objects.

The invention has been applied to a two way radio communication system in which radio transmitting and receiving means are located at each of two remote stations. Each station is provided with a comparing means for testing received signals to determine if the received signals are locally generated signals, or signals received from the opposite station. Transmitted signals are inverted so that a continuous wave on signal represents a spacing condition while a continuous wave off signal represents a marking condition. When it is desired to reverse the direction of transmission, the receiving station may send a prolonged break signal which is of a spacing nature. This causes the comparing means at the station which is transmitting to automatically place this station in receiving condition. Each comparing means includes a contact tongue associated with a receiving relay and a contact tongue associated with a testing relay in the transmitting circuit. As long as the signals received by the receiving relay are the same as the signals being received by the testing relay a station may keep transmitting. However, receipt of a break signal by the-receiving relay from the opposite station causes a slow to operate relay. to become energized by means of the above has been transmitting. At the station which has Vbeen receiving, transmission of the break signal automatically releases its direction control relay.

A second embodiment of the invention features the use of a home record printer and a receiving only printer-at each station. The home record printer is automatically conditioned when a station is about to transmit while the receiving only printer is disabled. At the station which is about toreceive the home record printer and transmitter are automatically disabled while theryhome record printer is conditioned for receipt of:` the incoming message. Such a system may prove quite advantageous where it is desirable to seg- `regate incoming messages from outgoing messages.

A third embodiment of the invention relates to the use of an alternate direction control which automatically functions at the end of a message to reverse the direction of transmission by sending a break signal to the opposite station.

A better understanding of the present invention may be had by reference to the detailed description which follows when read in conjunction with the drawings wherein:

Fig. 1 is a schematic circuit illustration of one embodiment of the invention;

Figs. 2 and 3 represent a schematic circuit illustration of a second embodiment of the invention; and

Figs. 4 to '7, inclusive, represent a schematic circuit illustration of a third embodiment of the invention.

With reference to Fig. 1, the first embodiment of the invention will now be described. At the left side of Fig. 1 is represented a west station, while at the right side of the same iigure is represented an identical east station. Hence, it will be noted that in the ensuing description, like parts at each station will be similarly numbered with the alphabetical designation W or El appended, according to Whether or not the part referred to is at the west or east station. It will be understood that duplicate descriptions of what occurs at. both the west and east will not bei given except where such descriptions may facilitate a better understanding of the invention. Outlying telegraph stations IllW and 10E are shown respectively associated with the west land east stations. However, such outlying stations may, of course, be located at the same site as the station'to which each is associated.

Station 10W includes a conventional arrange- 3 ment of transmitting contacts I IW and a receiver selector magnet I2W. When signals are being transmitted from West to east, a direction control relay ISW is unoperated at the West station While the corresponding relay ISE at the east station is operated. The transmitting circuit for station IDW under these conditions is as follows: From ground, through the winding of selector magnet I'ZW, through transmitting contacts IIW andga break key MW, over line IEW and leads VI'IW, ISW through contact tongue I9 (now closed)r 'of direction control relay ISW, over leads 11W and 22W, through the winding of slow to release relay 23W and through the winding of transmitting relay 24W. tongue 26W of relay 24W in response to a marking condition of relay 24W willvmove to an open position and in response to a spacing condition will move to a closed position. Thus, the signals are now inverted, causing a testing relay 21W to repeat such inverted signals, for a purpose which will hereafter appear, and also causing radio transmitter 28W to transmit a continuous wave on signal for spacing and a continuous Wave off signal for marking. Y

With direction control relay ISW unoperated, its contact tongues 29, 3|, 32, I9 and 33 remain in their unattracted position. With contact tongue 29 against its back contact, an obvious circuit is made for transmitting antenna 34W. With contact tongue SI on its Vback contact a circuit is made for signal lamp 36W and with the same Contact tongue on its front contact a circuit is made for signal lamp SIW. The signal lamps just described will thus'indicate the direction of transmission.

Now as radio signals are transmitted, receiving antenna 38E at the east station receives the signals for radio receiver 39E to accordingly operate receiving relay 4IE. Thus, operation of contact tongue 42E of receiving relay 4IE opens and closes the circuit extending over leads 22E and I'IE to receiving selector magnet I2E'as was described in connection with the west'st'ation. It will be noted that signals received vby receiving relay II IE are now reinverted back to theirinormal condition since in response to a carrier wave on condition, which is spacing, it'causes opening of contact tongue 42E and in response to a carrier wave oi condition, which is marking, it'causes closure of contact tongue 42E.

Signals transmitted by the west station .are also received by the westlstationantenna 38W and similarly cause operation of receiving relay AIIW and contact tongue 42W. However, operation of contact tongue 42W1does not cause echo signals to be impressed onreceiving selectormagnet I2W since leadsf22W and I'IW are held closed with contact tongue I9 of direction control relay I3W in its unattracted position as was initially described above. However, `at the east station contact tongue I9 of relay ISE is'in its open-fposition due to the energizationof directioncontrol relay ISE.

As testing relay 21W responds to the outgoing signals, its contact tongue 43W moves between its front `and back contacts and, at the-same "time, contact tongue 44W of receiving relay IIWV also moves between its front and back contacts Vas the outgoing signals are locally received. When a spacing signal is received by relay 2'IW,'its contact tongue 43W will beattracted while at the same time contact tongue #IIIW is attracted by r'e'- ceiving relay IIIW. When marking `signals are being transmitted an opposite condition is ef- It will be noted that the contact 1' fected. Hence, as long as the signals received by receiving relay 4IW are local signals, a circuit cannot be completed over leads 46W or 21W for slow to operate relay 48W from grounded contact tongue 33W of direction control relay ISW. Circuit closures for a very slight length of time due to lag in contact tongue operation between relays MW and 21W are insucient to operate the slow to operate relay 48W.

If it is now assumed that the east station desires to' interrupt transmission from the west station, break key HIE is operated which releases relay 23E to break a locking circuit for direction 'control relay ISE, extending through contact tongue 69E of slow to release relay 23E, over lead 5'IE 4and through contact tongue 32 of direction control relay ISE.A Thus, as direction control relay ISE releases, the antenna 34E is connected due Vto closure of contact tongue 29, lamp 36E is illuminated by operation of contact tongue SI fand lamp 31E is extinguished. The transmitting circuit extending over leads IIE and v22E -is `now placed in operating'condition as contact tongue I9 falls away. Now, when the steady spacing Vsignal is received at the west station, re ceiving relay MW will remain steadily energized, upsetting the 'testing operation of contact Ytongue 43W of relay 2TW and contact tongue 44W of receiving relay lIIW. In other words, as soon as the rst marking impulse-is received by testing relay 27W lafter the steady operation of receiving relay '4 IW, slow to operate relay 48W will now operate and complete `a circuit extending through contact tongue l50W and over lead 52W for direction control relay ISW, which now lo'cks up through contact tongue 49W of slow to release relay 23W. lIt is understood, that relay 23W will be retained operated as normal signals con'- taining marking impulses pass 'therethrough-and will only lde`energze when a steady spacing signal is received. Thus, with vdirection control vre'- lay ='I 3W energized 'and Y'direction control relay I'SE de-energized, transmission may now rtake place ffrom'station IDE .to's't-ation Y10W.

With reference to Figs. 2 and 3 the second embodiment of 'the invention -will n'o'wbe described. Description'oi thefrst embodiment of the invention will not be duplicatedexcept ywhere neces'- sary for a `full understanding Iof the invention. `Affeatur'e of this embodiment "of the 'invention'i's the `use of home 'record''printersl IIW, IUI'E land receiving only printers `I 02W, 'IME in conjunction with transmittersIlSW, I'SE.

"Operable under the'cont'rol of direction -relay ISW, V'is a newly added contact tongue II14W which lin its unattracted'position completes Yan obvious circuit extending lover "lead "IIWffor relay I 07W andra Ltransitiitter` start magnet 'I 08W. With relay IO'IW operated, transmitting contacts IUSW `are in the Ytransmitting circuit extending through make before break contact tongue I I IW and through'break key MW to lead I'IW as in the rst embodiment-of theinvention. rItwill be noted that the v transmitting vcontacts I09W are'in serieswith -selector'magnet II2W of home record printer IUIW when contact ltongue 'I-I IW ofrelay'IU'IW isin its attractecl'position. yClosure of make before break contact ltongue I ISW by operation of relay yIlll maintains -a marking Vcondition vover 'lead IIW 'for `selector magnet I IEW or" receivingonlyzprinterl I02W when trans- -mitter IUBW is Asending 'signals -to 'the receiving only lprinter 'IUZE'fat the east station. It will, of course, Abe understood that whateverfis described i at the west .station Lwill be .the .same as similarly numbered .parts at the east station.

The break signal :is transmitted exactly as was described in the first embodiment of the inven tion. Let it now be assumed that the west station is transmitting ysignals to the east station and that the latter station wishes to interrupt transmission to send a message from `east to'west. Transmission of the `break signal lfrom the east station by operation of key |4E will cause the release of direction controlrelay |3E at the `east station and operation of direction control `relay |3W. at the west station. Closure of contact tongue IME due to therelease of relay |34 causes relay IIHE and start magnet IUBE of transmitter |I|3E -to operate. This .places transmitter |03E in condition tosend signals over lead I'IE as was described in connection Wfiththe west station. `As relay IIIIW releases due to the .opening of contact Vtongue |04W of relay '|3W, contact tongue IIIW moves to its unattracted position, and an obvious circuit is closed extending through transmitting contacts |09W and selector magnet I |2W, placing a -steady marking condition on selector magnet ||2W and preventing the operation of home recorder IDIW. As contact tongue |I3W similarly moves to its unattracted position, receiving only printer IIlZW is placed in receiving condition since a circuit now extends .from lead I'IW, through break key MW, through contact tongue II3W, and overlead IMW to theselector magnet ||6W of the receiving only printer |02W. Release of contact tongue I IIWbS7 `relay Ill'IW causes a signal lamp II8W to-beextinguished, while operation of contact tong-ue I-I'IE by relay IME causes i signal lamp I ISE to be illuminated. These signal lamps .give a ready indication of the direction of transmission. AIt willbe observedthat operation Vof break key IdE-causes `a steady marking current to be impressed on selector magnet |I6E until yrelay III'IE has a chance to operate and provide -the steady marking current through contact tongue HSE. n

A third embodiment kof the `inventionv disclosed in Figs. 4, 5, 6, and '7 will now be described. This form of the invention features the use of alternate direction control .means whereby `an automatic break signal is transmitted by a station at the end of a message tof'automa'tically reverse the direction of transmission. For accomplishing Such automatic reversal, an endofmess'age responsive mechanism such as`is `disclosed in the patent of Goetz, No. 2.2962845 an'dindicated generally by numerals |W\and2Il|E is employed.

The end of message responsivemechanismsform y a part of their respective transmitters 202W and 202E. At the west station, .thecircuit extending from contact tongue |04W of Adirection-control relay I3W over lead I nowrproceeds .through relay IUT-W, over lead 203W,through transmitter start magnet 204W, through contact pair 206W, over lead 201W, through the winding of relay 208W, and through contact blades 209W and 2| IW to ground. Itis assumed that the west station is now transmitting to the east station and that the various parts are conditioned as shown in Fig. 5.

When the end of a message is reached, an end of message feeler 2| 2W pivots counterclockwise withdrawing its shoulder 2I3W from beneath latch 2|4W, which now pivots clockwise under impetus of spring 2|6W. By means of pin 2 I'IW carried by latch 2|4W, gooseneck lever 2|8W is caused to pivot clockwise, opening contact blades 209W, 2| IW and closing blades 2| IW and 22|W.

Thus .the circuit for :start magnet 204W is 'broken and transmitter .202W comes to rest. Closure rof contact .blades vZIIW, .22IW, provides a circuit over lead 222W .for .the left-hand winding rof double wound relay 223W. Relay 223W now locks up through its contact tongue 224W, contact vtongue 226W of slow to operate relay 221W and through the winding of the last mentioned relay. .As contact tongue .228W is attracted, the transmitting circuit extending over leads 24|W through break .key |4W and over lead I'lW is broken sending a steady .spacing signal to the east station. After `a short predetermined interval, slow to operate relay22`|W operates, opening i contact tongue 226W and .breaking the locking circuit for relay 223W. At .thesame time .contact tongues 229W and 23|W are 'attracted by 'relay 221W. Closure of contact tongue 229W, closes the line circuit extending over lead I'IW and thereby terminates the break signal. A locking circuit is now maintained for relay 227W which extends through its 'contact tongue 23|W and tongue 232W of relay 233W .(now operated). Relay 233W is at thistime operated over the following circuit: From vvnewly added contact tongue 234W .of direction control relay |3W (now'operated) over lead 236W and through the winding of relay 233W. It is apparent that when the direction of transmission again changes, relay |3W will be released, the just described circuit for relay 233W will be broken, and relay 221W will be released.

As relay 223W attracts contact tongue 243W a circuit is completed to slow to operate relay 244W. After antenna 34W has functioned to transmit the break signal to the east station, relay 264W operates and establishes a circuit through its contact tongue 246W and over lead 247W for the winding of slow to operate relay II8W. As relay 48W operates, it closes contact tongue 56W which operates direction control relay ISW as described in the first embodiment of the invention.

When the break signal is received at the east station, direction control relay ISE is de-energized as relay 23E becomes de-energized and breaks the locking circuit for relay |3E extending through tongue 49E. It will be understood that an operator will manipulate bar 236W after the end of a message is reached to close contact blades 209W, 2 ||W and insert a new message tape, so that when the east station completes transmission of a message, the direction of transmission Will again be reversed so that the west station transmits to the east station. Opening of contact blades 209W, 2| IW causes relays 223W and 244W to release. For a more complete description of the operation of the end of the message device 2DIW, reference should be had to the laforementioned Goetz patent. The direction of transmission may also be reversed by operation of break keys MW, ME in the manner described in the second embodiment of the invention. When relay 208W is operated, signal lamp 248W is illuminated and when the same relay is released signal lamp 242W is illuminated.

It must be understood that various changes and modications may be made in the present invention without departing from the spirit or scope thereof and that in some instances the system may be successfully used in wired systems as well as in radio systems. The invention should therefore not be limited in scope except as defined by the appended claims.

What is claimed is:

1. A telegraph system including a transmission path, a rst and second station associated with said path, a transmitter, a home recorder and a receiving onlyA recorder at each of said stations, testing means including means responsive to outgoing and incoming signals at each of said stations for testing received signals to determine if the received signals are locally generated signals or signals received from the opposite station, means at each of said stations associatedwith said testing means and responsive to the receipt of signals from the opposite station for thereby automatically disabling said transmitter and home recorder and conditioning said receiving only recorder at the station receiving said signals, and means at said opposite station for disabling said receiving only printer and conditioning said transmitter and home recorder upon transmission of said signals.

2. A telegraph system including a rst and second station, a transmitter, a home recorder and a receiving only recorder at each of said stations, an end-of-message responsive mechanism at each of said stations, break signal transmitting means at each of said stations, said end-ofmessage responsive mechanism being operable at the termination of each message to operate said break signal transmitting means to send a break signal to the opposite station, means at each station responsive to the receipt of said break signal for automatically disabling the receiving only recorder and conditioning the transmitter and home recorder thereat, and means at each station operable upon transmission of said break signal therefrom for automatically disabling the transmitter and home recorder thereat and conditioning the receiving only recorder for reception of signals from the opposite station.

3. A radio telegraph system including a rst and second station, radio transmitting means at each of said stations for transmitting signals, radio receiving means at each of said stations for receiving signals, testing means at each of said stations including a first relay for testing incoming and outgoing signals and a second relay for testing outgoing signals, said second relay coperating with said rst relay for determining if the signals are locally generated signals or signals received from the opposite station, and

means at each of said stations associated with going signals for determining if the received signals are locally generated signals or signals received from the opposite station, and means at each of said stations associated with said testing means and responsive to the receipt of signals from the opposite station for enabling said opposite station to gain control of the direction of transmission.

5. A radio telegraph system including a first and second station, radio transmitting means at each of said stations for transmitting signals, radio receiving means at each of said stations :for receiving signals, testing means at each of said stations for testing signals received at each station to determine if the received signals are locally generated signals or signals received from the opposite station, and means at each of said stations associated with said testing means and responsive to a prolonged signal of one nature received from the opposite one of said stations for automatically enabling said opposite station to gain control of the direction of transmission.

6. A radio telegraph system including a rst and second station, a transmitter, a home record recorder and a receiving only recorder at each of said stations, radio transmitting means at each station for transmitting signals, radio receiving means at each station for receiving signals, testing means at each of said stations for testing signals received at each station to determine if the received signals are locally generated signals or signals received from the opposite station, means at each of said stations for transmitting a prolonged signal of one nature and for thereby conditioning the transmitter and home recorder and disabling the receiving only recorder at the station transmitting said prolonged signal, and means at each of said stations associated with said testing means and responsive to the receipt of said prolonged signal from the opposite station for automatically disabling said transmitter and said home record recorder and conditioning said receiving only printer for operation at the station receiving said prolonged signal.

MARTHA W. C. POTTS, Easecutrix Under the Last Will and Testament 'of Louis M. Potts, Deceased.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS 

